1. Field of the Invention
The present invention relates to a plasma processing apparatus and a plasma processing method used for manufacturing semiconductors.
2. Description of the Related Art
Conventionally, in field of manufacturing semiconductor devices, methods of performing a process, such as an etching process or a film-forming process, by using plasma have been adopted. As one of the methods, a radial line slot antenna (RLSA) type plasma processing apparatus that generates plasma by propagating microwaves from a slot formed in a radial line slot plate into a processing container is well known (for example, refer to Patent Document 1). An RLSA type plasma processing apparatus has an advantage of performing a plasma process on a large-sized semiconductor wafer evenly and rapidly, because plasma of low electron temperature may be evenly generated at a high density. As an example of the plasma process, a process of etching of a substrate surface performed by using an HBr gas is well known. As another example of the plasma process, a process of etching an SiN film formed on a surface of a substrate by using a processing gas including a CF4 gas and a CHF3 gas is well known.
In an RLSA type plasma processing apparatus, microwaves are propagated inside a processing container via a dielectric disposed on a ceiling surface of the processing container. A processing gas introduced in the processing container becomes plasma due to energy of the microwaves, and a surface of a substrate is processed. In general, an introduction unit for introducing the processing gas into the processing container is disposed, for example, in a side surface of the processing container. Recently, an introduction unit for introducing the processing gas has been provided in a ceiling surface of the processing container, in addition to the introduction unit disposed in the side surface of the processing container (for example, refer to Patent Document 2).
Patent Document 3 discloses a parallel plate type plasma processing apparatus. In the parallel plate type plasma etching apparatus, a pair of an upper electrode and a lower electrode that are parallel with each other are provided in a processing container, a radio frequency is applied to the lower electrode, and at the same time, a substrate is placed on the lower electrode to be etched. In order to improve uniformity within a surface of the etched substrate, the upper electrode is divided into a center region for supplying a processing gas to a center of the substrate, and a peripheral region for supplying the processing gas to a peripheral portion of the substrate. In addition, a ratio between introducing amounts of the processing gas to the center portion and the peripheral portion is controlled (Radial distribution control (RDC)).
3. Prior Art Reference
(Patent Document 1) Japanese Laid-open Patent Publication No. 2009-99807
(Patent Document 2) Japanese Laid-open Patent Publication No. 2008-251660
(Patent Document 3) Japanese Laid-open Patent Publication No. 2009-117477